US and Russian companies make thorium fuel alliance

20 April 2007

Thorium Power of the US and Red Star, a nuclear design agency owned by the Russian government, have signed an agreement for Thorium Power's 'seed and blanket' fuel designs to undergo irradiation testing with the goal of moving towards use in commercial reactors.

The contract is subject to approval by the Russian Federal Agency for Atomic Energy (Rosatom), which is expected before summer 2007. In the meantime, ongoing testing will continue at Russia's Kurchatov Institute.

Thorium Power recently announced successful completion of three years of thermal-hydraulic experiments, when experimental thorium fuel rods were subjected to pressure and temperature conditions that could be found in commercial light-water reactors during an emergency. Thorium Power executive vice president Andrey Mushakov described the new alliance with Red Star as enabling an accelerated programme leading to demonstration of the fuel assemblies in a full-size commercial reactor. "Red Star and Thorium Power have already cooperated in a study of the engineering and regulatory requirements to use Thorium Power's fuel designs in a Russian VVER-1000 reactor, and we have agreed on a detailed implementation plan," he said.

Thorium is more abundant than uranium and, although not fissile, it can be used as nuclear fuel because when it is irradiated with slow neutrons fissile uranium-233 is produced. This is typically achieved by using a 'blanket' of thorium around a 'seed' of uranium fuel. A thorium fuel cycle leads to the production of only very small amounts of plutonium, and is seen as being more proliferation-resistant than the uranium fuel cycle. It also has advantages over uranium fuel in terms of the radiotoxicity of the spent fuel. Thorium fuel has been studied in various countries for at least 30 years, but abundant uranium supplies have in the past lessened the need for its full development for commercial use.